GRAND RAPIDS – Wes Leonard, Fennville's star athlete who died suddenly Thursday after hitting a game-winning shot, had an undiagnosed enlarged heart that triggered an abnormal heartbeat, according to Dr. David Start, who performed the autopsy on the 16-year-old.

Start, Ottawa County's medical examiner, said Friday that Leonard's heart muscle was nearly twice as large as it should be and that the Fennville athlete had the condition, officially known as dilated cardiomyopathy, for years.

“He had a marked enlargement in both the left and right ventricles,” Start said. “That would lead to a sudden arryhthmia and this particular condition is associated with sudden death.”

Start said the stress Leonard placed on his heart through athletics could have played a role in the fatal flare-up but it can't be easily explained why it happened during the final game of the school's perfect regular season.

“Why at this event as opposed to another basketball or football game, I don't know,” Start said. “We don't know what caused it in this particular case.”

Start plans to do additional microspcopic analysis of the teen's heart, but that may prove inconclusive as well.

Leonard, who also starred as the school's quarterback, could have been born with the defect or it could have developed from a viral infection years ago.

It was not associated with a recent illness that Leonard battled through last week, Start said. Leonard was treated for an upper respiratory infection, his family told the forensic pathologist.

“There was no trauma, no evidence of infectious disease and it is not tied to any active infection,” Start said.

“There is scar tissue in the heart which shows it is something that has been present for years.”

Start said emergency responders and doctors at Holland Hospital tried to resuscitate Leonard for more than two hours before he was pronounced dead at 10:20 p.m. Thursday. A defibrillator was used during treatment, Start said.

“Every possible attempt to save this young man was made,” he said. “In my opinion, they did everything that could be done.”

Start said a routine physical would not detect the condition and an examining physician would have no reason to order an echocardiogram, essentially an ultrasound of the heart, that would have diagnosed the enlarged heart.

The doctor has recommended to Leonard's family that they undergo the test to determine if any relatives have the same condition.

“His heart was very large, very abnormal,” Start said. “There was no indication that he had any prior symptoms.”